Note 19 — Chapter VIII · THE GASTRÆA THEORY
Reading edition
My distinction (1872) between the primitive gut and mouth and the later permanent stomach (metagaster) and mouth (metastoma) has been much criticised; but it is as much justified as the distinction between the primitive kidneys and the permanent kidneys. Professor E. Ray-Lankester suggested three years afterwards (1875) the name archenteron for the primitive gut, and blastoporus for the primitive mouth.